How to Correctly Calculate the Average of Multiple Columns in SQL?

Error in Calculating Average of Multiple Columns

In an attempt to determine the average of multiple columns in a table named 'Request,' a SQL query was employed:

Select Req_ID, Avg(R1+R2+R3+R4+R5) as Average
from Request
Group by Req_ID

However, instead of producing the intended average, the query returned the sum of the values. To correct this error, the query can be modified to the following:

SELECT *,
       (SELECT AVG(c)
        FROM   (VALUES(R1),
                      (R2),
                      (R3),
                      (R4),
                      (R5)) T (c)) AS [Average]
FROM   Request 

This revised query utilizes subqueries and the AVG aggregate function to correctly calculate the average for each row in the 'Request' table.

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